should i buy a 77 mercury 850

I currently have a 66 johnson 60 hp v4 that sucks gas badly and parts are rediculously expensive. I know the newer motors are supposed to be cheaper for parts and get better gas milage. I would also like to have more power for my 1990 larson 15 ft. I can get a 1977 mercury 850 for $350 and it comes with a trailer i can sell to recoupe some of the money. my question is Will this motor get any better milage, are parts cheaper, and is it more reliable. Are there any known problems with this motor? It also has power trim and a charging system which my motor does not.

Re: should i buy a 77 mercury 850

IMHO i believe its definately the superior motor, just check the compression, make sure everything is within 15 psi of each other, dam right this is the better buy, not only to mercs looks better and go faster then omc, but they smell better too, your engine is an inline 4 2 carbs 2 reed blocks, your gonna have more horsepower and mercs are clearly faster so you may increase gas mileage... the 850's were sexy as **** man... very well built motors

Re: should i buy a 77 mercury 850

my 75 850 mercury pushes my 15.5' 1970 Galaxy trihull pretty darn fast, its run great for the PO and only has had minor problems for me....i know from experience the carb floats are a bad 2 piece design and fail, good thing is the new replacements are one piece, better material and only about 11 bucks each...put new floats in it, and all new fuel line including the pump and primer bulb, then have fun!!

Re: should i buy a 77 mercury 850

For the price it sounds good, but just wiring harnesses will cost $400 or more
I have that exact year and model and haven't been able to find carb kits or a
lower unit seal kit, i believe more parts are available for the 1973-1975 models. I ended up making my own wiring harness which was somewhat time consuming and still ended up costing about $150. I really like the motor
and it's been reliable except for the wire harness and starter dying. I'm getting about 5.5-6mpg running 32mph with a 21p prop on a 16' sylvan sportster. Top speed is about 37mph for me but I think 40mph is possible with
proper setup. Also these motors had aluminum wiring so check out the trigger, stator and switch box wiring, mine had severe rot and would just crumble when handled. Another motor you might want to find is a 70-75hp
omc 3 cylinder I hear they're good midsize motors as well.

Re: should i buy a 77 mercury 850

i would say the old mercs are good but parts are getting hardr to find i would spend a little more money and get something alittle newer

Re: should i buy a 77 mercury 850

i have 74 850 merc and runs good had no problems since i had carbs rebuilt i would buy it for 350 it would definetly be an upgrade on horsepower and those old mercs are pretty powerful

Re: should i buy a 77 mercury 850

Sorry its been forever but i did eventually buy the motor. I rebuilt the carbs and it runs great. now i am replacing the floor and transem. next season it will be like a new boat.